Is there a really, really good reason that the "OfficeBackgroundTaskHandlerRegistration" task (see it in Task Scheduler, Microsoft, Office) must run every hour? This is what it says that it does: "This task initiates Office Background Task Handler, which updates relevant Office data."
I ask, because it runs officebackgroundtaskhandler.exe in such a way that it flashes a window (itself) on the screen. Only instantaneously to be sure, but it's noticeable, especially once you catch onto what's happening. You can run the task manually if you want to see it without waiting.
Why doesn't the task use one of the many tricks to hide a window from displaying?
Insider Fast on Win10.